Dedicated to Professor V. I. STARTSEV on the occasion of his 70th birt.hday-Combining mechanical acoustic and SEM investigations, the influence of various heat treatments on the mechanical stability of the intermetallic phase V,Ga of multifilanientary Cu-Ga/V composites is analyzed. The destruction
Acoustic emission analysis of stable and unstable fracture in high strength aluminium alloys
โ Scribed by H. Cai; J.T. Evans; D. Boomer
- Publisher
- Elsevier Science
- Year
- 1992
- Tongue
- English
- Weight
- 950 KB
- Volume
- 42
- Category
- Article
- ISSN
- 0013-7944
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โฆ Synopsis
Crack extension in some high strength aluminium alloys was investigated using acoustic emission measurements. The tensile ductility varied with prior heat treatment and was strongly correlated with the volume fraction of coarse intermetallic particles retained in the structure. The acoustic emission characteristics reflect the macroscopic properties and an important source of emission was found to be the cracking of coarse intermetallic particles. A short, stable crack extension by dimpled, transgranular tearing was observed in tests on precracked specimens. The specimens were found to emit strongly above a 35 dB threshold when stable crack extension started at K,,. Unstable, intergranular crack extension was observed after the stable crack extension at K,. The cumulative energies of acoustic emission events were found to be linearly related to the macroscopic fracture energy for both stable and unstable crack extension.
๐ SIMILAR VOLUMES
Experiments have been made to investigate the effect of mean stress on fatigue crack propagation in +in. (12.7mm) thick specimens of six aluminium alloys of high and low fracture toughness. The resuits are presented in terms of the stress intensity factor range, AK and the R value where R is the rat